Device for forming ports in thin-walled tubes



g- 1 1966 F. A. SERAVIN ETAL 3,266,356

DEVICE FOR FORMING PORTS IN THINWALLED TUBES Filed May 14, 1964 4Sheets-Sheet l Aug. 16, 1966 F. A. SERAVIN ETAL 3,266,356

DEVICE FOR FORMING PORTS IN THIN-WALLED TUBES 4 Sheets-Sheet 5 Filed May14, 1964 IIIIIIIIIIIIIIIIIIIIIJ.'

DEVICE FOR FORMING PORTS IN THIN-WALLED TUBES Filed May 14, 1964 4Sheets-Sheet 4 l l 33 -03 34 4 l I L J I g I 3,266,356 Ice PatentedAugust 16, 1966 3,266,356 DEVICE FOR FORMING PORTS IN THlN-WALLED TUBESFelix Alexandrovich Seravin and Andrei Nikolaevich Maltlakov, both ofVoronezh, U.S.S.R., assignors to Experimentaljuy Nauchno-IssledovatelskyInstitute Kuznechno Pressovogo Mashinostrocnija, Voronezh, U.S.S.R.

Filed May 14, 1964, Ser. No. 367,367 4 Claims. (Cl. 83181) Thisinvention relates to devices for forming ports in thin-walled tubes, andmore particularly to devices for forming ports in thin-walled tubes by anibbling or punching operation.

The known devices for punching ports in tubes comprise a mandrel-diearranged on a stationary quill, a punch mounted on a press side,automatic means for rotating and moving lengthwise the tube by one step.The means for longitudinally moving and rotating the tube comprisesvertical racks secured with the press slide to cooperate with ahorizontal rack coupled to a hooked lever.

A hole is punched in the tube during the down stroke of the press slide,and during the upward stroke of the slide, the tube is rotated by thehooked lever, the free end of which drops into one of the punched holes.During the rotation of the tube, the hooked lever is actuated to movelaterally as a result of which the tube is simultaneously shifted in thelongitudinal direction.

The known devices have the drawback that a single punch is adapted toproduce holes of identical size, several holes being produced, whereverrequired, with equal spacing.

An object of the present invention is to provide a device for producingports in thin-walled tubes, a single punch being utilized for nibblingholes of variable size.

Another object of the present invention is to provide a device of thetype permitting generation of ports in variable spaced relationship toeach other in the tube treated.

A further object of the invention is to provide a device of theabove-mentioned type to produce ports in thinwalled tubes by anautomatic process.

Still another object of the present invention is to provide a device forproducing ports in thin-walled tubes, said device ensuring very closetolerances in the punched holes and their spaced relationship in a moreeificient manner than heretofore known.

In view of the above and other objects, the present inventioncontemplates the provision of a device for generating ports inthin-walled tubes comprising a slidemounted punch, slide actuatingmeans, a mandrel die,

means for longitudinally moving and rotating the tube treated, and aprogramming unit for insuring the movement of the tube throughpredetermined distances, the punch according to the present inventionhaving a crosssection corresponding to the size of the smallest port tobe formed in the tube.

The slide-actuating mechanism includes means for causing the slide toassume a non-operating position without being stopped, said meanscomprising a wedge cooperating with a spring-urged support coupled tosaid mechanism and actuated by a power cylinder mounted on the frame ofthe device.

The mechanisms used for longitudinally moving and turning the tube areprovided with motors comprising hydraulic boosters that amplify thetorque and are controlled by servomotors.

The device further comprises means for synchronizing the operation ofsaid mechanism for longitudinally moving and turning the tube, and aslide-actuating mechanism adapted to mark port contours in succession.

Therefore, the device according to the invention enables the automaticgeneration of ports of variable dimensions and in diverse spacedrelationships along the tube by means of nibbling said tube with asingle punch which insures very close tolerances in the size and spacingof the ports-punched.

The invention is described hereinafter, by way of example, withreference to the accompanying drawing, in which:

FIG. 1 shows a longitudinal section of the device ac cording to theinvention;

FIG. 2 is a section taken along line AA in FIG. 1;

FIG. 3 is a section taken along line B-B in FIG. 1;

FIG. 4 is a cross-sectional view of the punch for producing the smallestsize port;

FIG. 5 is a development of the surface of a tube with ports of variousshapes generated by means of a single punch according to the presentinvention;

FIG. 6 shows diagrammatically the means whereby synchronized operationof the mechanisms for longitudinal motion and rotation of the tube iseffected with the slide actuating mechanism; .and

FIG. 7 shows a portion of FIG. 1 on enlarged scale.

Referring to FIG. 1, a tube 1 is placed in the clearance defined betweena hollow mandrel-die 2 and a cage 3. The mandrel-die is mounted at oneend on a cantilever quill 4 fixed in a bracket 5 which is secured on aplate 6.

A press frame '7 with the cage 3 mounted thereon is fixed to the plate6. The cross section of the punch 8 (see FIG. 2) corresponds to theminimum size port to be cut, the punch being mounted on a slide 9 of thepress.

The slide 9 and the punch 8 are driven in reciprocating motion with afrequency preferably of 1,000 strokes per minute, whereby ports ofvarious shapes and size can be nibbled by a single punch in this manner.

The press slide 9 with the punch 8 fixed thereon is set in motion bymeans of a toggle mechanism 10 mounted in frame 7 which, in turn, isactuated by an eccentric shaft 11 also mounted in frame 7 and driven byan electric motor 12.

During reciprocation of the press slide, the tube 1 is shifted in alongitudinal direction or rotatedin respect to the die by a nibblingpitch t (FIG. 4) which is less than the size a of punch 8. The motion oftube 1 in the direction of arrow C is timed with the reciprocatingmotion of the punch in such a manner that successive portions of tube 1are fed under the punch for the nibbling of ports of a given shape.

Scrap or waste in the form of small punchings drops through the dieopening into space b of die 2 and is discharged by compressed air, whileany Waste which does not drop into space b is removed during thelongitudinal motion of the tube.

The longitudinal motion of the tube is carried out by means of a feedscrew 13, a nut 14 and a carriage 15 (see FIG. 1) travelling onball-type guide ways 16, and carrying a work-holding device comprisingthe springloaded holding fixtures 17, which are caused by a nut 18 witha tapered inner surface, which clamp the tube by means of holes providedin the tube near its end.

The nut 18 is threadably connected with a sleeve 19 assembled inbearings 20 and 21 of the carriage 15. A pinion 22 is rigidly fitted onthe sleeve 19 and is in mesh with a gear wheel 24 which is keyed on afeed shaft 23 of the tube turning mechanism. Thus, the tube turningmechanism is adapted for turning the tube around its axis, whereby thetube can be both rotated and longitudinally displaced.

After the contour of port 25 has been nibbled or punched, the feedmotion of the tube under the punch for nibbling the next port 26 iscarried out without stopping the slide 9 and the punch fixed in thelatter. For

this purpose, a wedge-acting device is provided on the upper part of thepress frame 7 for the displacement of the slide from its operativeposition, this device being connected with a bearing-block support 27and toggle mechanism 10. 'The bearing-block support 27 is constantlyurged to an upper inoperative position by springs 28 which urge theblock 27 to the top wall of the frame. A wedge 29 is slidably supportedon the bearing block 27 and is connected to the piston of a pneumaticcylinder 30. When compressed air is admitted into the cylinder 30, itspiston pushes the wedge 29 along an inclined surface of thebearing-block 27. This causes the wedge 29 to lower the bearing-block 27until it is thrust against the shoulders 31 of the frame '7. In thisposition the press slide 9 and the punch 8 are in their lower operativeposition. When compressed air is evacuated from the pneumatic cylinder30, the spring 32 returns the piston and wedge 29 to their initialinoperative position until the block 27 will contact the shoulder of theframe 7. This causes the return of the toggle mechanism 10, the slide 9and the punch 8 to their intitial inoperative position all under theaction of spring 28. Simultaneously the rotary and longitudinal feedmotion of the tube for nibbling the next port is effected.

The operation of the pneumatic cylinder of the wedge mechanism iscontrolled by a slide valve air distributor actuated by a solenoid (notshown in the drawings) which receives command signals from a controlunit according to a given program (not shown).

The tube feed motion during the period of port nibbling is synchronizedwith the reciprocating motion of the punch 8 in such a way that feedingof the tube for a nibbling pitch is performed only during the idlestroke of the punch. To assure such synchronization the lengthwise feedmechanism and the tube turning mechanism are provided with torquehydraulic boosters 33 and 34 respectively (see FIGS. 1 and 6), which arecontrolled by step servomotors 3S and 36 (FIG. 6). Output shafts 37 and38 of hydraulic boosters 33 and 34 are respectively coupled with feedscrew 13 and feed shaft 23.

The shafts (not shown in the drawings) of step servomotors and 36, andtherefore screw 13 and feed shaft 23, are caused to rotate when thewindings of these servomotors are supplied with electric pulses Dcontinuously produced by blocking generator 39 mounted in the controlpanel.

In order to make tube I perform movements timed with those of punch 8,cam shaft 11 carries a pickup 40 (FIGS. 1 and 6), for instance, of aphotoelectric type for recording angular position. The pickup closes therespective electric circuit, whose signal indicated by arrowhead E (FIG.6) open electric valve 41 passable to pulses produced by blockinggenerator 35 during the no-load travel of the punch.

As a result, the winding of servomotors 35 and 36 are supplied inaccordance with a predetermined program through the commutating blocks42 and 43 of the servomotors, with only a certain portion of pulses tocause rotation of the servomotor shafts through a certain value incorrespondence with the nibbling pitch t.

Hydraulic boosters 33, 34 and 41 are powered by a common hydraulic pump44 (arrowheads F and G).

It should be noted that the embodiments described above and illustratedin the drawings are but preferable variants of the present invention.

Variations may be made in the form, size and arrangement of thecomponents. The above-described units can i. be, for instance,substituted for their equivalents, the location of individual componentscan be changed, and some units can be employed independently of theothers. However, all these variations are considered to be within theconcept and scope of the invention if defined in the accompanyingclaims.

What We claim is:

1. A device for forming ports in a thin-walled tube, comprising a platewith guideways therein; a frame mounted on said plate; a slide in saidframe for having a punch secured therein, said punch having across-section corresponding to the size of the smallest port to beformed in the tube; means in said frame to drive said slide inreciprocation; a driven cam shaft in said frame coupled to the lattermeans to drive the same; a bracket mounted on said frame; a mandrel diehaving one end secured in said bracket; a cage accommodating the otherend of said mandrel die and spaced therefrom by a clearance, said cagebeing mounted on said frame and said clearance serving for theaccommodation of a tube therein; a carriage supported for travelling insaid guideways of the plate and including means for clamping the tube inwhich the ports are to be formed; a mechanism for moving the tubelengthwise including a feed screw having one end mounted in said frameand an opposite end in said bracket and a nut secured in said carriageand engaged with the feed screw for being driven thereby; a mechanismfor turning the tube and including a feed shaft having one end securedin said frame and an opposite end in said bracket and having kinematicconnection with said means which clamps the tube; and means forsynchronizing the operation of said mechanism which lengthwise feeds thetube and the mechanism which turns the tube and the means which drivesthe slide in reciprocation to effect the forming of the outline of theports in the tubes.

2. A device according to claim 1, comprising means serving to withdrawthe slide from an operative positionto an inoperative position withoutstopping said cam shaft and comprising a displaceable wedge, aspring-urged support for said wedge and coupled to said means whichdrives the slide in reciprocation, and a power cylinder arranged on saidframe and coupled to the wedge for displacing the same.

3. A device as claimed in claim 1 wherein said clamping means comprisesa sleeve provided with radial openings and secured in said carriage, acoupling nut mounted in said sleeve and having a tapered inner surface,and spring-urged members extending through said radial openings of thesleeve and gripping the tube with their lower ends as the upper ends ofsaid members cooperate with said tapered surface of the coupling nut.

4. A device as claimed in claim 1 wherein said mechanisms which feed thetube lengthwise and turn the tube include respective motors, torqueboosters for said motors, and servomotors controlling said boosters.

References Cited by the Examiner UNITED STATES PATENTS 1,489,716 4/1924R-upe 83-188 2,180,331 11/1939 Hughes et a1. 83-36 2,648,381 8/1953Engel 8336 3,026,754 3/1962 Hartup 83-188 WILLIAM W. DYER, JR., PrimaryExaminer. L. B. TAYLOR, Assistant Examiner.

1. A DEVICE FOR FORMING PORTS IN A THIN-WALLED TUBE, COMPRISING A PLATEWITH GUIDEWAYS THEREIN; A FRAME MOUNTED ON SAID PLATE; A SLIDE IN SAIDFRAME FOR HAVING A PUNCH SECURED THEREIN, SAID PUNCH HAVING ACROSS-SECTION CORRESPONDING TO THE SIZE OF THE SMALLEST PORT TO BEFORMED IN THE TUBE; MEANS IN SAID FRAME TO DRIVE SAID SLIDE INRECIPROCATION; A DRIVEN CAM SHAFT IN SAID FRAME COUPLED TO THE LATTERMEANS TO DRIVE THE SAME; A BRACKET MOUNTED ON SAID FRAME; A MANDREL DIEHAVING ONE END SECURED IN SAID BRACKET; A CAGE ACCOMMODATING THE OTHEREND OF SAID MANDREL DIE AND SPACED THEREFROM BY A CLEARANCE, SAID CAGEBEING MOUNTED ON SAID FRAME AND SAID CLEARANCE SERVING FOR THEACCOMMODATION OF A TUBE THEREIN; A CARRIAGE SUPPORTED FOR TRAVELLING INSAID GUIDEWAYS OF THE PLATE AND INCLUDING MEANS FOR CLAMPING THE TUBE INWHICH THE PORTS ARE TO BE FORMED; A MECHANISM FOR MOVING THE TUBELENGTHWISE INCLUDING A FEED SCREW HAVING ONE END MOUNTED IN SAID FRAMEAND AN OPPOSITE END IN SAID BRACKET AND A NUT SECURED IN SAID CARRIAGEAND ENGAGED WITH THE FEED SCREW FOR BEING DRIVEN THEREBY; A MECHANISMFOR TURNING THE TUBE AND INCLUDING A FEED SHAFT HAVING ONE END SECUREDIN SAID FRAME AND AN OPPOSITE END IN SAID BRACKET AND HAVING KINEMATICCONNECTION WITH SAID MEANS WHICH CLAMPS THE TUBE; AND MEANS FORSYNCHRONIZING THE OPERATION OF SAID MECHANISM WHICH LENGTHWISE FEEDS THETUBE AND THE MECHANISM WHICH TURNS THE TUBE AND THE MEANS WHICH DRIVESTHE SLIDE IN RECIPROCATION TO EFFECT THE FORMING OF THE OUTLINE OF THEPORTS IN THE TUBES.